Repeated checksum mismatch installing portable-ruby, removing tarball does not resolve

[fadookie]

Output of brew config

eliot@mac ~ % brew config  
==> Downloading https://ghcr.io/v2/homebrew/portable-ruby/portable-ruby/blobs/sha256:d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf
###########################################################################################                                                                                                                    44.6%/opt/homebrew/Library/Homebrew/utils/helpers.sh: line 70: 10337 Filesize limit exceeded: 25   "${HOMEBREW_LIBRARY}/Homebrew/shims/shared/curl" "$@"
Error: Checksum mismatch.
Expected: d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf
  Actual: fccf4d3edba3426330b3cfc0b967e14df421953da2b57796a34253808ee00647
 Archive: /Users/eliot/Library/Caches/Homebrew/portable-ruby-3.3.7.arm64_big_sur.bottle.tar.gz
To retry an incomplete download, remove the file above.
Error: Failed to install Homebrew Portable Ruby (and your system version is too old)!

Output of brew doctor

eliot@mac ~ % brew doctor 
==> Downloading https://ghcr.io/v2/homebrew/portable-ruby/portable-ruby/blobs/sha256:d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf
###########################################################################################                                                                                                                    44.6%/opt/homebrew/Library/Homebrew/utils/helpers.sh: line 70: 10650 Filesize limit exceeded: 25   "${HOMEBREW_LIBRARY}/Homebrew/shims/shared/curl" "$@"
Error: Checksum mismatch.
Expected: d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf
  Actual: fccf4d3edba3426330b3cfc0b967e14df421953da2b57796a34253808ee00647
 Archive: /Users/eliot/Library/Caches/Homebrew/portable-ruby-3.3.7.arm64_big_sur.bottle.tar.gz
To retry an incomplete download, remove the file above.

Description of issue

I am migrating from an Intel 2020 MacBook Air to an M4 Pro MacBook Pro 2024 running macOS 15.2. I used Migration Assistant to copy my data over but brew was not installed so I tried installing it. First, I tried the familiar shell method, but kept getting the following fatal error during installation:

==> Downloading and installing Homebrew...
remote: Enumerating objects: 290673, done.
remote: Counting objects: 100% (129/129), done.
remote: Compressing objects: 100% (104/104), done.
fatal: fetch-pack: invalid index-pack output
Failed during: /usr/bin/git fetch --quiet --progress --force origin

So, I tried the new pkg installer method via Homebrew-4.4.19.pkg. This succeeded, but when trying to run brew update or brew selfupdate or seemingly any other brew command I get the portable-ruby checksum mismatch error. I read other issue reports where the suggested remedy was to remove the tarball cache and retry. I have tried this many times, it redownloads and gets the same error again.

Some other versions that might be relevant:

eliot@mac ~ % type -p zsh 
zsh is /bin/zsh
eliot@mac ~ % /bin/zsh --version
zsh 5.9 (arm64-apple-darwin24.0)
eliot@mac ~ % type -p ruby 
ruby is /usr/bin/ruby
eliot@mac ~ % ruby --version
ruby 2.6.10p210 (2022-04-12 revision 67958) [universal.arm64e-darwin24]
eliot@mac ~ % type -p brew
brew is /opt/homebrew/bin/brew
eliot@mac ~ % brew --version
Homebrew 4.4.19

[gromgit]

To confirm that you're pulling down the correct data:

curl -sL -H "Authorization: Bearer QQ==" https://ghcr.io/v2/homebrew/portable-ruby/portable-ruby/blobs/sha256:d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf | sha256sum -

If the above outputs a different checksum than d9faa...02bcf, then something's interfering with your download.

Separately, there's an error in both your diagnostic outputs that you may have missed:

/opt/homebrew/Library/Homebrew/utils/helpers.sh: line 70: 10650 Filesize limit exceeded: 25   "${HOMEBREW_LIBRARY}/Homebrew/shims/shared/curl" "$@"

What's the output of ulimit -a?

[fadookie]

Thanks for the prompt reply.

I did notice that filesize limit exceeded error but wasn't sure what to make of it.

eliot@mac ~ % ulimit -a
-t: cpu time (seconds)              unlimited
-f: file size (blocks)              10240
-d: data seg size (kbytes)          unlimited
-s: stack size (kbytes)             8176
-c: core file size (blocks)         0
-v: address space (kbytes)          unlimited
-l: locked-in-memory size (kbytes)  unlimited
-u: processes                       4000
-n: file descriptors                10240

Here's the curl command:

eliot@mac ~ % curl -sL -H "Authorization: Bearer QQ==" https://ghcr.io/v2/homebrew/portable-ruby/portable-ruby/blobs/sha256:d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf | sha256sum -
d9faa506c014dedc0b034a68103ba75c9a58242f4d6c67b6ca0f649c39602bcf  -

Seems to be that d9faa...02bcf we're expecting so it looks like the filesize limit issue is the root cause here. According to the man page for zshbuiltins, ulimit -f oddly specifies the number of 512-byte blocks allowed, so it had been limited to 5 MiB files! Seems like a ridiculously low limit, so I added this line to my ~/.profile:

ulimit -f 1000000 1000000

Which should increase ulimit -f to 512 MiB. After reloading my shell, the brew update succeeds!

Thanks for the help. I think the error messaging could be improved here, perhaps a sanity check for a certain size ulimit -f and logging an error or a warning before trying to download a file would be a good idea, I can file a separate issue for that suggestion.

[fadookie]

Issue filed: Homebrew/brew#19167